On Tue, Jun 25, 2019 at 05:51:27PM +0900, Masahiro Yamada wrote: > Commit 0126be38d988 ("kbuild: announce removal of SUBDIRS if used") > added a hint about the 'SUBDIRS' replacement, but it was not clear > enough. > > Multiple people sent me similar questions, patches. > > https://lkml.org/lkml/2019/1/17/456 > > I did not mean to suggest M= for building a subdirectory in the kernel > tree. > > >From the commit 669efc76b317 ("net: hns3: fix compile error"), people > already (ab)use M=... to do that because it seems to work to some extent. > > Documentation/kbuild/kbuild.txt says M= and KBUILD_EXTMOD are used for > building external modules. > > In fact, Kbuild supports the single target '%/' for this purpose, but > this may not be noticed much. > > Kindly add more hints. > > Makefile:213: ================= WARNING ================ > Makefile:214: 'SUBDIRS' will be removed after Linux 5.3 > Makefile:215: > Makefile:216: If you are building an individual subdirectory > Makefile:217: in the kernel tree, you can do like this: > Makefile:218: $ make path/to/dir/you/want/to/build/ > Makefile:219: (Do not forget the trailing slash) > Makefile:220: > Makefile:221: If you are building an external module, > Makefile:222: Please use 'M=' or 'KBUILD_EXTMOD' instead > Makefile:223: ========================================== > > Suggested-by: Christoph Hellwig <hch@xxxxxx> > Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> Nice! Acked-by: Sam Ravnborg <sam@xxxxxxxxxxxx> Sam